This invention relates to drawing instruments for drawing an ellipse which can accurately draw an ellipse as desired in a simple operation.
Despite rapidly increasing recent demand and interest in drafting machines or the like, particularly in a stereography, there is now not available a suitable draftsman's outfit for drafting an ellipse as a basic figure thereof. Known devices have limitations such that (a) one semi-ellipse is first drawn and thereafter the device is rotated 180.degree. to draw the other semi-ellipse thus finishing a one complete ellipse, or (b) an extremely small ellipse or an ellipse close to a straight line is difficult to make with known devices, or (c) a drawing pen cannot be used, or (d) the operation is so complicated as to take skill, and so on.
Under actual circumstances, there was generally used, a template of synthetic resin formed with holes or openings, which could only make an ellipse of fixed angle and size as determined by the cut-out or opening.